This is a painfully frustrating reminder that women get talked over by men. It's one thing to have one panelist talk over another, but to have the moderator, who is explicitly in charge of facilitating a panel discussion, be the one to drown out a panelist is just unacceptable. Yes, "not all men" do this, but the fact that this continues to happen in such visible and public settings, where presumably people are on "their best behavior", would suggest that it happens even more in more private situations. Research has shown that groups where speaking is more distributed are more successful at solving problems, and explicitly teams with more women are more successful: https://www.theatlantic.com/business/archive/2015/01/the-sec...
I will take this story as another reminder to be aware of situations where I might be dominating a conversation, and I hope you will too.